Drill for glass



(No Model.)

WITNESSES:

E. HIGHAM.

DRILL FOB. GLASS.

Patented 0013.5, 1886.

INVENTOR I d444, BY W ATTORNEYS UNITED STATES PATENT ()FFICE.

E D\VIN HIGHAM, OF CHICAGO. ILLINOIS.

ADRILL FOR GLASS.

SPECIFICATION forming part of Letters Patent No. 350,132, dated October 5. 1886,

Application filed August 30,1886. Serial No 219.279. (No model.)

To all whom, it may concern.-

Be it known that I, EDWIX Hunt-in, of Chicago, in the county of (look and State of Illinois, have invented a new and Improved Drill for Making Holes in Glass and other Substances, a full and exact description of which is set forth in the following specifiea tion, reference being had to the accompanying drawings.

My invention has particular reference to metallic rotating drills for the drilling ofholes in glass and other vitreous substances. Heretofore all drills for that purpose have been made with a sharp or angular point, and great difliculty is had in making the drill bite or take hold of the material to be drilled without putting so great a pressure upon it as to endanger the breaking of the glass.

My invention is designed to remedy this difficulty, and to this end I make the drill beveled on two sides to form a wedgeshaped point with a knifeedge at right angles to the axis of the drill-bit.

Referring to the drawings, Figure 1 is an enlarged side View of my improx'ed drill enlarged to about double its ordinary size. Fig. 2 is an edge view, and Fig. 3 is a corner or perspective view, of the same.

Similar letters refer to similar parts throughout the drawings.

A is the top of the drill, which may be shaped to fit into an ordinary brace, drillpress, or other boring-machine arranged to impart a rotary motion to the drill B.

1), Fig. 1, is the commencement of the taper of the drill and is its maximum width, from which point it tapers on its sides to form the wedge-shaped point, as shown in Fig. 2, ter minating in the knife-edge O, at right angles to the longitudinal axis of the drill, as shown, and on its edges the drill tapers slightly downward from the pointB E, Fig. 2, its maximum thickness leaving the corners square and the knife-edge G slightly shorter than the width of the drill at its widest part B D, Fig. 1. The knife-edge 0 should preferably be in the form shownviz., straight and at right augles with the longitudinal axis of the drill; but it may be slightly curved, or it may be at an angle varying slightly from right angles to said longitudinal axis without changing its effectiveness for the purposes desired.

The operation of my drill is as follows: The drill is fitted into a brace or other apparatus l'or revolving it upon its longitudinal axis, and is then placed at right angles to the glass or other material to be drilled, with the knife-edged point resting firmly against such material. The point is moistened with water or turpentine in the usual manner, and light pressure is applied to the drill, and the drill is then rotated upon its axis by the brace or other apparatus under constant light pressure. The knife-edge will from the be ginning of the pressure and motion take hold of and out the material to be drilled with the whole working .l'aee of the edge, and as long as such pressure and rotary movement is continued will work its way into the material, making a round hole, the square corners of the drill above the knifeedge operating as reamers to enlarge the hole to the full size of the drilLas it enters the material, the size of the hole being regulated by the diagonal tl1ickness of the drill. The pressure required is about one-half the pressure required with any other drill, and by the use of this drill the cost of drilling holes in glass is decreased at least fil'ty per cent.

Having thus described my invention, what I claim, and desire to secure by Letters Patcut, is

1. A drill for making holes in glass and other material, having a beveled,poiut terminating in a straight knile-edge as a cuttingface, and to be rotated upon its longitudinal axis, substantially as shown and described.

2. A drill for making holes in glass and other material, provided with a wedge-shaped point terminating in a knife-edge at right angles or nearly at right angles to the longitudinal'axis of the drill, substantially as shown and described.

3. A drill for making holes in glassjior other material, having a sharp straight cutting-face at or nearly at right angles with the longitudinal axis of the drill, and the sharp corners or supplementary cutting-edges B 0,

to complete the hole to be drilled, substansupplementary cutting-edges to enlarge and tiall; as shown and described. complete the hole as drilled, substantially as 4. In a drill for making holes in glass and shown and described. other vitreous 0rbrittlesubstances,t11e straight EDWIN HIGHAM. 5 knife-edge O at right angles to the longitudi- Witnesses:

nal axis of the drill as a cutting face, in WM. D. GOPPERNQLIQ, combination with the sharp corners B O, as JOHN D. 

